A Study for Participants With Relapsed Cutaneous T-Cell Lymphoma

Inclusion Criteria:

   - Histologically confirmed mycosis fungoides or Sezary Syndrome.

   - Stage IB to IVB disease at screening.

   - Recurrent or refractory disease after at least 1 prior systemic therapy.

   - Have adequate organ function defined as:

      - Hepatic: total bilirubin ≤1.5 times the upper limit of normal (ULN); alanine
      transaminase/aspartate transaminase (ALT/AST) ≤2.5 times the ULN.

      - Renal: serum creatinine ≤1.5 times the ULN.

      - Adequate bone marrow reserve: platelets ≥75 * 10^9/Liters (L); absolute
      neutrophil count (ANC) ≥1.0 * 10^9/L.

   - At least 30 days must have passed since other treatment for CTCL.

Exclusion Criteria:

   - Receiving concurrent treatment for CTCL.

   - Unable to swallow tablets.

   - Receiving high potency oral or topical steroids. Low potency oral steroid may be
   permitted in participants who have been on a stable dose for at least 4 weeks prior to
   screening. Oral or topical antihistamine is allowed.

   - Unable to discontinue use of carbamazepine, phenobarbital, or phenytoin.

   - Have a serious concomitant systemic disorder or Human Immunodeficiency Virus (HIV).

   - Have a serious cardiac condition such as myocardial infarction within past 6 months,
   angina, or heart disease as defined by the New York Heart Association (NYHA) Class III
   or IV.

   - Have electrocardiogram (ECG) abnormalities.

   - Are pregnant or breastfeeding.